Division of labor is a fundamental component of complex social systems, in groups as diverse as insects and mammals. In all social groups, division of labor involves specialization by individuals on certain tasks. However, for division of labor to function in a variable environment, it must allow for changes in task performance. In honey bees, Apis mellifera, task specialization depends on: (1) age polyethism, with individuals of different age groups performing different tasks within a colony, and (2) genetically-based individual preference for certain tasks. The long-term objective of this project is to determine the mechanisms for individual and societal task regulation in honey bees. More specifically, it will examine mechanisms for and constraints on individual flexibility in foraging behavior, and determine how individual variation in task performance is integrated into colony-level regulation of foraging. The project will use a variety of behavioral and genetic techniques, including use of instrumental insemination to construct honey bee colonies containing a variety of worker genotypes, and allozyme electrophoresis and DNA analyses (RAPD markers) to identify genetic subfamilies within colonies. Three principle questions will be addressed: (1) What are the relative contributions of individual flexibility and genotypic diversity to colony-level foraging plasticity?, (2) How do genetic and developmental constraints on individual behavioral flexibility constrain foraging behavior at the colony level?, and (3) How well do models of foraging flexibility developed using domesticated honey bee colonies predict the behavior of social groups under conditions of natural selection? This study will provide information crucial to understanding the evolution of division of labor in complex social systems, and mechanisms of behavioral flexibility in social insect colonies.